In an explosive interview, former New York Observer Editor-in-Chief Elizabeth Spiers said that President Donald Trump's son-in-law and White House senior advisor Jared Kushner told her that Trump never believed the "birther" conspiracy theory, but found it effective because "Republicans are stupid and they'll buy it."

Spiers was appearing on MSNBC's "The Point with Ari Melber" Sunday to discuss Kushner's role in the White House and the increasing scrutiny he is facing over his ties to Russian officials and bankers.

Kushner, Spiers said, was never particularly interested in journalism or its principles, but bought the New York Observer because it was a respected news organ and "he was drawn to the brand."

Other Observer coworkers have called Kushner a "sh*thead" and a know-nothing who "has bought his way into everything ever (with money he got from his criminal father)" and who is "deeply insecure and obsessed with fame."

Melber asked Spiers on Sunday about Kushner and his famous father-in-law's embrace of "birtherism" -- the conspiracy theory that former President Barack Obama was born in Kenya and was not a U.S. citizen and to confirm something she revealed in her writing.

"I told jared I was particularly appalled by his father-in-law's birtherism stance," Melber read from Spiers' essay. "He rolled his eyes and said, 'He doesn't really believe it, Elizabeth. He just knows republicans are stupid and they'll buy it.'"

"He really said that to you?" Melber asked.

"Yeah," Spiers said.

Watch the video, embedded below: